Habitat & RangeHairy brown seaweed grows on rock in the mid- to low intertidal and in tidepools. It is a spring annual, and is found on moderately protected shorelines from Kodiak Island, Alaska to Baja California, Mexico.

Similar SpeciesHaplogloia kuckuckii has been recorded on the BC coast, and is distinguished from H. andersonii by the presence of hair-like filaments on only the ends of the branches. While it is currently listed as a distinct species, H. kuckuckii and H. andersonii may actually be the same species.